Grinding or polishing machine



Dec' 2, 1947. BARNA GRINDING OR POLISHING MACHINE Filed April 29, 1946 2Sheets-Sheet 1 I v V Dec..2, 1947. BARNA 2,431,907

GRINDING OR POLISHING MACHINE Filed April 29, 1946 2 Sheet 2 i l 11 1/12 9?? 131,;\ I18 47\ "4: I I? 9 Patented Dec. 2, 1947 GRINDING QRPOLISHING MACHINE James J. Barna, B elleville,

Lazar e Kaplan & Sons, Inc.,

N. J., assignor to New York, N, 31.,

a. corporation of New York 7 Application April 29, 1946, Serial No.665,737.

5 Claims. 1

This invention relates to grinding or polishing machines, and moreparticularly to machines of this character which are used forthflpolishing of diamonds and other precious stones.

In the polishing of diamonds, difiiculty is often encountered in workingon certain portions of the stone, such as, for example, the girdle ofthe stone, and unless the polishing operation upon this part of thediamond .is done by hand operation and by skilled workers, the polishingof the girdle portion of the stone is often left. undone. An objecttherefore, ofthe present invention, is to provide an apparatus by meansof which the girdle and other normally inaccessible portionsof the stonemay be readily and effectively polished without especial skill on thepart of the operator.

Another object of the invention is to provide, in a machine of thischaracter, means by which the polishing operation isperformed by arotating polishing wheel, rotating in several directions, whereby thepolishing is done in such a manner nd r various angles that a completeand ex.- ceptionally uniform polishing result is attained.

In hereinafter describing the apparatus as a polishing machine intendedfor work upon diamonds, I wish to be understood. as not limiting themachine to such use, since the polishing or grinding functions performedby the apparatus can be used for a multitude of other grinding purposes.

In the accompanying drawing, wherein an illustrative embodiment of theinvention is dis, closed, Fig. 1 is a side elevation of apolishingmachine constructed in accordance with the invention; Fig. 2 isa top plan View of the same; Fig. 8 is a sectional view on the line 3-.of Fig. .4, look.- ing in the direction of the arrows; Fig. 4 is an endview of the machine, looking at the right end of Fig. 1; Fig. 5 is asectional View transversely of the machine, looking at the gearing, andFig. 6 is an end view of the machine, looking at the left end of Fig. 1.

In the drawings, l indicates the base plate of the machine. At one endof the base is located the vertical end .wall 2 and spaced therefrom andlocated parallel thereto, is a second vertical .wall 3. Wall 2 isprovided with a centrally located bearing 4, and wall 3 with the bearing5., a shaft 6 being rotatively mounted in these hearings. Secured on theshaft 6 is a pulley 1 adapted to be engaged by a belt extending from anelectric motor to thereby rotate the shaft 6 at the required Speed.

At one end, the shaft is provided with a clevis 3 nw a shaft M is rtativelv u ted said 2 shaft M having its axis disposed at right anglesto the longitudinal axis of the shaft 6. Secured upon the shaft I4 isthe polishing wheel l5, so that it will be apparent that when the shaftI4 is rotated, a rotation ofthe polishing wheel on an .axis parallel toits plane will take place. On one end of the shaft I4 is attached apinion l6 which is in mesh with a large stationary ring gear H, thelatter being provided with a flange l8 secured to aface of the uprightwall 3.

It will be clear from the foregoing, that the arrangement described issuch that when the shaft 5 is rotated by a motor (not shown) and whichdrives the pulley "I, the clevis l3 will be rotat-ed, this acting torotate the shaftlA about a transverse axis. As such rotation of theshaft It takes place, it is caused to also rotate about itsownlongitudinal axis by-the rotation of the pinion tijin meshedengagement with the fixed ring gear l1. As a result of thearrangementdescribed, the polishin Wheel 15 will not only be rotated about its ownaxis but will also be rotated about the axis of the shaft 6, or in otherwords, about an axis extending parallel to the plane of the polishingWheel.

Provided at the opposite sides of the base plate are thebrackets 2!! and2|, said brackets being secured to the base by the .screws 24. Thesebrackets act as-a support for a frame 22 pivotally held betweenthebrackets 26 and 2| by means of thescrews .Or bolts 2,3, the pivots forthe frame 2 :.bei e thusiocated adjacent tothe lower end of the frame.

Rotativelymol nted in the lowercro-ss-bar 36- of the. frame 2; isahollowshaft 25 in which a vertically movable stem 26 is located, the upper endof said stern being provided with a seat 38 (Fig. 2) $9 the di mond 3.9to be polished. The s em 26 isprov ded with an elongated, longitudinallyextending slot 2'! through which a cross-pin 28 extends, thisslot-and-pin arrangement permitting raising and lowering movement of thestem 26 within. the limits of the slot. The stem is nor- .3.2113 r edipward vby means of the coil spring 31 located within the shaft 25 andoperative aga nst the lower end .of the stem 26 as clearly 5. .6 1 inFig. 2.

The diamond 39 to be polished, is thus placed up the seat 38 and is heldthereon by means of a threaded pin 40, threadably received through thetop cross-bar-29 of frame 22. The pin 4|! is provided .witha head 41 bywhich it may be adjllsted throughthe cross-bar 29, and with the not4204, by means of which its adjustment can be maintained and repeatedlysecured. A feeler pin 3 41 extends through one of the sides of the frame22 and aids in securing the desired location and positioning of thediamond 39 on the seat 38.

The diamond being carried by the seat 38, is rotated relative to thepolishing wheel [5, and the rotative movement of pin 26 is secured bymeans of a gear 44 secured at the lower end of shaft 25, and driven by aworm 46 (Fig. 3) secured on a shaft 45 rotative in bearings 42. Thebearings 42 are in the form of plates attached to the sides of the frame22 by the screws 43. Shaft 45 is provided with a pulley or other means,not shown, by means of which it may be driven from the motor whichrotates shaft 6, or from a separate motor or other source of power.

The adjustment of the diamond to be polished to bring it to and from theperiphery or edge of the grinding wheel I5, is secured by swinging theframe 22 on its pivots 23 to or from the wheel. Extending across thetops of the upright plates 2 and 3 and secured to the tops of saidplates, is a bar 30, having a tapered end portion 3|, the end of whichserves as an abutment or seat for the end of an adjusting screw 3Ia.Screw 3Ia is threadably adjustable through a vertical post 32 risingfrom the top of the frame 22. From the top of the post 32 projects a pin33 which serves as an anchorage for one end of a coil spring 34 whichhas its opposite end attached to the upright post 35 attached to andrising from the top of the bar 30.

The arrangement just described is such that the spring 34 normally tendsto draw the frame 22 toward the polishing wheel I5 to bring the stone 39against the edge of the Wheel. The distance which the frame is drawn bythe spring 34 is regulated by the adjusting means 3|, 3la as justdescribed, and through this arrangement a precise adjustment of thediamond in respect to the polishing wheel is secured. To aid inmaintaining a precise adjustment and thereby accurately regulating theextent to which the diamond is polished, it is desirable that no endplay be permitted in the shaft 6, carrying the polishing wheel [5.Accordingly, the shaft 6 is maintained under endwise pressure by meansof a leaf spring 9 secured at one end to a stud I l by the screw I2. Theopposite end of the spring 9 exerts pressure on a ball 8 held in arecess in the end of the shaft 6. Through this arrangement, wheel I5 isheld against movement axially ofthe shaft 6 and its position relative tothe diamond upon which it is operating is consistently maintained.

From the foregoing, the operation of the machine will be readilyunderstood. The diamond 39 or other object to be polished, is placedupon the seat 38 and is held thereon by the contact of the end of thepin 40, the stone being accurately set on the seat by use of the feelerpin 41. By adjustment of the screw 3| a the extent to which the diamondis ground or polished can be regulated.

When the diamond is in place, as above described, shafts 45 and 6 areset in motion. Rotation of shaft 45 will cause rotation of the stem 26-about a vertical axis, so that the diamond held on the seat 38 of thestem 26 will be rotated. As shaft 6 is rotated it will rotate thepolishing wheel l5 about the longitudinal axis of the shaft 6 or aboutan aXis parallel to the plane of the polishing wheel l5. As shaft 6rotates as above described, the pinion I6 is caused to rotate throughits mesh with the ring gear [1, this causing rotation of the shaft I4and spinning of the wheel l5 about the axis of the shaft l4. It willthus be obvious that the polishing wheel not only rotates about its owncentral axis, or about the axis of the shaft l4, but it is also rotatedabout the axis of the shaft 6, and thus by this arrangement a veryeffective po1i:hing result is secured, and particularly on the girdleand on other normally inaccessible parts of the diamond. While the wheelI5 is operating in the manner just described, the diamond is also beingrotated about a vertical axis. The relative sizes of the pinion l6 andthe ring gear II are to be noted since it is desirable to rotate thepolishing wheel about the axis of shaft I 4 at a higher speed than theshaft 6 is rotated. In the present arrangement, a four-toone gear ratiois used, but this can be modified to suit different requirements.

While I have shown and described one embodiment of the invention, it isobvious that the same is not to be restricted thereto, but is broadenough to cover all structures coming within the scope of the annexedclaims.

What I claim is:

1. In an apparatus of the character described, a main shaft providedwith a bearing at one end, a short shaft rotative in said bearing, apolishing wheel mounted on said short shaft, a pinion carried on theshort shaft, a fixed ring gear with which the pinion meshes, a pivotedframe, a diamond-holding device carried by said frame and adapted tohold a diamond against the periphery of the polishing wheel, means fornormally urging the frame toward the polishing wheel, adjusting meansfor limiting the extent of movement of the frame toward the polishingwheel, and means for rotating the diamondholding device in the frame.

2. In an apparatus of the character described, a base, uprights arisingtherefrom, a main shaft rotatable in said uprights, a clevis at one endof said shaft, 3, short shaft rotatively mounted in said clevis, apolishing wheel secured on the short shaft, the axis of said short shaftbeing disposed transversely to the longitudinal axis of the main shaft,a pinion carried by the short shaft, a ring gear surrounding the mainshaft and secured to one of the uprights, the pinion being in mesh withthe ring gear, a support for a diamond, and means for adjusting saidsupport to and from the polishing wheel to hold the diamond thereonagainst the polishing wheel,

3. In an apparatus of the character described in claim 2, wherein thesupport for the diamond is provided with a rotatable seat for thediamond, and means for rotating said seat.

4. In an apparatus of the character described comprising, a support,spaced uprights arising from the same, a main shaft rotative in thesupports, a ring gear secured to the face of one of the supports, themain shaft extending through the center of the ring gear, a short shaftrotativel carried at the end of main shaft, the axis of the short shaftbeing at right angles to that of the main shaft, a polishing wheelcarried by the short shaft, a pinion secured on the short shaft and inmesh with the ring gear, means for exerting endwise pressure on the mainshaft, a pivoted frame, a. diamond seat in said frame, means fornormally urging the frame toward the polishing Wheel, means foradjustably limiting the movement of the frame toward the polishingwheel, and means for rotating the diamond seat within the frame.

5. In an apparatus of the character described, a base, a shaft rotatableabove the base, supporting means rising from the base and rotatablysupporting the shaft, one of said supports carrying a fixed ring gear,the shaft extending through said ring gear, a bearing at the end of theshaft, a polishing wheel rotatively mounted in the bearing, a projectionfrom said polishing wheel carrying a pinion in mesh with the fixed ringgear, a frame pivoted above the base, a diamond-holding device carriedby the frame and holding a, diamond against the periphery of thepolishing wheel, means for normally urging the frame toward thepolishing wheel, adjustable stop means for limiting the extent ofmovement of the frame toward the polishing wheel, and means for rotatingthe diamond-holding device in the frame.

JAMES J. BARNA.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

